1. Field of the Invention
The present invention relates to a blower fan, and more particularly, to a blower fan having an improved structure to increase an efficiency of the blower fan and miniaturize the blower fan. Particularly, the present invention is directed to a blower fan in which the number and shape of blades thereof are optimized to increase a blast capacity and thereby miniaturize the blower fan.
2. Description of the Related Art
Blower fans are used to suck and blow a large amount of air. Among the blower fans, the present invention is focused on turbo fans, which suck air in an axial direction and blow the air in a radial direction, while changing a flow direction of the air by 90 degrees with blades.
Generally, a blower fan includes a shroud formed in a direction of an air inlet, a hub formed in a direction of an air outlet, and a plurality of blades fixed to the shroud and the hub.
Meanwhile, the blower fan of the related art has a large D1/D2 ratio, where D1 is an inner diameter and D2 is an outer diameter of blades, such that the related art blower fan has an large size and as a result, an indoor unit of an air conditioner in which the blower fan is to be installed is also enlarged.
Further, to improve static pressure properties of the blower fan, the blades of the blower fan are inclined in a direction of rotation of the blower fan. However, an air flowing along the blades during rotation of the blower fan is subjected to more pneumatic resistance owing to the inclination of the blades, such that an efficiency of the blower fan is lowered. Consequently, when the blower fan is used, the blower fan must be driven at a high speed to blow a required amount of air because of the lower efficiency, thereby consuming more power.